Corrosion inhibitor for light petroleum solvents and fuels



INHIBITOR r on'monr PETROLEUM SOLVENTS AND FUELS Arlie A. ()Kelly, Lewiston, and Clarence A. Weltman, Niagara Falls, N. Y., assignors to Alox Corporation, Niagara Falls, N. Y., a corporation of New York No Drawing. Application June 23, 1954 Serial No. 438,852

5 Claims. (Cl. 52 .5)

CORROSION This invention relates to the provision of corrosion inhibitors adapted for use in gasoline, jet fuel (JP#4), and other light petroleum fuels and light petroleum solvents. The entity JP#4 is a designation, in a U. S. Government Specification MIL-F-5624B, of a low vapor pressure species of Fuel, Aircraft Turbine, and Jet Engine, which specification is generally restricted to fuels consisting of hydrocarbon compounds of petroleum origin.

The novel corrosion inhibitors of the present invention are designed to be effective in concentrations from 6 to 50 parts per million (p. p. m.) of fuel or solvent, and to protect storage tanks, pipelines, transport vessels and, in general, all equipment for transporting and storing light petroleum products. Since moisture or liquid water is almost always present as contamination from some source, corrosion is normally a serious problem. Storage tanks always breathe. With changing temperatures over the course of 24 hours, the vapors in a tank expand or contract. When they contract, air is drawn into the tank and the moisture contained in the air may condense. During long tank storage, considerable volumes of water may be introduced, especially during humid weather. The dangers of corrosion in light fuels storage and transport lie in the damage to costly equipment and contamination of the fuel by particles of iron oxide which may scale off the Walls of the pipe or tank.

The requirements of a good light fuels inhibitor (LFI) can be summarized as follows:

(a) It shall protect all equipment while in contact with the inhibited fuel and water.

(b) It shall protect metal equipment for short periods after the inhibited fuel is drained from the equipment. Thus, after a tank is drained-or partly drainedthe exposed metal surface shall be protected against atmospheric corrosion.

(c) The LFI shall be completely and strongly adsorbed on. the metal surfaces it is protecting. In this way the residual protection described under b can be efit'ected. This adsorption is also necessary so that equipment can be treated by contact with LFI-containing fuels. Subsequent batches of fuel then require less LFI for continued protection of tanks and equipment. Subsequent lots of fuel may require only 6-10 p. p. m. for continued protection because the metal already has an adsorbed film of inhibitor.

(d) A further manifestation of b and c above occurs in sea-going tankers. load of fuel and then fill the tanks with salt water as ballast for the return trip. The use of inhibited fuel greatly reduces corrosion difiiculties on the return' trip. Corrosion is not completely eliminated by the thin adsorbed filmof LFI.

(e) The LFI shall not increase gumming tendency or oxidation tendency of the fuel.

The tanker may deliver a 2,861,874 Patented Nov. 25, 1,958

. 2 r deactivators anti-oxidants, TEL, or other additives normally used in the fuels.

It has been found that a light fuels inhibitor, meeting the above criteria, can be produced by admixing a major amount of polymerized linoleic acid-hereinbelow more specifically described-with a minor but effective amount of an oil-soluble dimethyl .dialkyl ammonium chloride having the formula:

wherein each R represents an alkyl group having from 8 to 18 carbon atoms.

Preferably the quaternary ammonium salt used is a product, sold under the trade-name Arquad 2C, of which the alkyl groups are composed of a mixture of the following:

y Percent Octyl (C 8 Decyl (C 9 Dodecyl (C12) 47 Tetradecyl (C 18 Hexadecyl (C i 8 Octadecyl (C 10 It shall be compatible perfonnance-wise with metal inStoddard Solvent, oils,

' waxes, resins, fuels.

Preferably the composition'ofv the present invention is composed essentially of approximately 10-90% by Weight of the polymerized linoleic acid and approximately -10% of the dimethyl dialkyl ammonium chloride (50% active in isopropanol). The composition may, and preferably does, include also a suitable amount of a petroleum solvent or oil to impart a desirable fluidity to the composition for ease of handling and dosage: this latter ingredient is not, however, an essential part of the composition.

It has been discovered thatthe composition of the present invention affords a striking illustration of synergistic effect-as more particularly will be brought out in the hereinbelow portions of this disclosure sub-titled Table I and Table II-in that essentially any combination of (a) polymerized linoleic acid and (b) dimethyl dialkyl ammonium chloride is exceedingly more effective as a light fuels inhibitor than is either (a) or (b) alone. A ratio of 90% Empol 1022 to 10% Arquad 2C? is preferred because it combines outstanding effectiveness with economy. Increasing the ratio of Arquad 2C beyond about 10% materially increases. the cost of the additive without material improvement in the elfectiveness of the composition. With 40 parts by weight of this mixture there may be included from about 40 to about 80 parts, preferably 60 parts, by weight of Stoddard Solvent or other hydrocarbon ,s olvent as fluidizing'agen't or' carried V a W l.

The effectiveness of the above-described light fuels inhibitor" was established by the' following experimental work: 7

' A; TEST METHOD] (l) The test' method used to evaluatelight fuels inhibitors was ASTM-D-665-49T. However, our tests were run at a temperature of 80 F. The ASTM method calls for 140 F. In this test, a polished steel rod is immersed in a beaker containing 300 ml. of inhibited fuel and 30 ml. of synthetic sea water. The mixture is stirred rapidly so that'the oil and 'sea water flow over the test rod. The. length of time the testis runis arbitrary. We have" selected 24 hours as prescribed in ASTM D-6 65.

The test rod is'exan 'ined periodically for visual signs of rust. -When 5-10% of the surface is rusted we have recorded it as a failure. Any product noted as a pass shows no corrosion after 24 hours of exposure to the rapidly stirred fuel-sea water mixture.

' (2) Todetermineresidual rust protection, -a complete test,..as.described above, .was run After 24'hours, the inhibited fuel ..was removed from the beaker and replaced by 300ml. of uninhibited fuel. Additional sea Water. was also added. Stirring was continued until failure of. the specimen.

' B. FUELS SELECTED Most of the development work concentrated on three fuels:

(1) 36/40 B. distillate"... Kerosene.

(2) High test. gasoline.

(3) Jet fuel -1 ..1. JP #4 (procured from U. S.

7 Air Force).

C. PROCEDURE All test work was based on combinations of Empol 1022 and Arquad 2C as the active components.

To prepare solutions at very low concentrations of additive, concentrates containing 1% additive in a light petroleum solvent (Varsol) were used; The'following summary shows the amounts of Concentrate used:

2 g. of 1% additive in Varsol)-H98 g. fuel=0.005%

additive in fuel (50 p. p. m.)

1 g. of (1 additive in Varsol)-H99 g. fuel=0.0025% additive in fuel (25 p. p. m.)

0.5 g. of (1% additive in Varsol)-{399.5 g. fuel =0.0012% additive in fuel (12 p. p. 1 11.)

0.5 g. of 1% additive in Varsol) +799.5 g. fuel =0.0006% additive in fuel (6 p. p. m.)

350 ml. of test fuel were added to the beaker. The test rod, stirrer and thermometer were assembled, and stirring started. After 30 minutes of stirring, 50 ml. of fuel Wereremoved by pipette, and 30 ml. of seawater added. The time of addition of sea water is taken-as the time of starting the test.

D. RESULTS The results for jet fuels are summarized in'Table I. l

The results for hi-test gasoline are summarized in Table II.

The results for kerosene are not summarizedbecause they are similar in magnitude to those for gasoline.

Table III' presents selected data demonstrating residual rust protection. 5 a a Table IV summarizes the effects of a high concen tration .o in ga o n on th tanda 81 dete m nat on Table l [ASTM-D-fifiS-49T. Results for inhibited .TP4 jet fuels] Percent p. p. 111. ASTM- 5 Additive Composition oomposicomposi- D-665 Time tion in tion in Result (Hrs) JP4 JP! p 11022. 81882 g8 1 (b) A mixture of 10% Ar- 0.0006 6 20 0 quad 2o 50% and 00% 0. 0012 12 24 Empol 1022. 0.0025 25 24 (c) A mixture of 30% Ar- 0.0006 6 20 quad 2C (50%) and 70% 0.0012 12 24 (511 11011022. f 7 A 0.0025 25 Pass 24 7 mixture 0 0.0012 12 257 Rust... 24 15 fig fg g and 50% i 0. 0025 25 Pas s 24 (e) A mixture of 70% Ar- 0 0006 6 Rust" 20 figfifg9 and 30% 0.0012 12 Pas s 24 m A mixture of 90% 0 0012 12 257 Rust.-. 17 gg gg? and 10% o. 0025 25 Pas s 24 -Ar uad 2O 50 0.005 50 507 Rust.-- 4 20 i 'lmef 100% Rust..- 2

40% rust after 16 hrs. 7

Table II 25 [ASTM-D-665-49T. Results for inhibited hi-tes t gasolinel Percent p. p. m. Additive Composition composieomposi- Result Time tion in tion 111 (Hrs) Gasoline Gasoline (a) Empol 1022 8-88? iZJ E g: M 10%.? 0: 0006 6 24 gg fidg w and 9 0. 0012 12 Pass 24 (c) A mixture of 30% 'Ar- 0.0006 6 Pass 24 5 ggfi g and 70% 0.0012 12 Pass 24 (d) A mixture 50% 0. 0000 6 307 Rust.-- 24 g gg fi g and 50% 0. 0012 12 Pes s 24 (e) A mixture 70%Ar' 0.0000 0 Pass 24 gggfi f gg and 30% 0. 0012 12 Pass 24 0 A mixture f 007 Arv V 2G (50%) M51070 0. 0012 12 20% Rust." V g:

Emp 01 1022 0.0025 25 Pass (g) Arquad 2C (50%) 0. 005 50 40% Rust 4 Table III RESIDUAL RUST PROTECTION [In ASTM D665 49T rust test.]

1 After 200101511 of 50 Percent uninhibited gasoline Composition in Gasoline Result Time, hours Em 011022 0.0025 507'Rust'. 3 Arqiiad 2o 50%) 0.0025 "le 2 A mixture of 90-Empol 1022 and 8: f i "Mmwd 2O (50%) 0. 0025 20% Rust... 8

Table IV 1 1 EFFECT OF LEI ON QUIET DETERMINATIONS IN GASOLINE Copper ASTM ASTM Dish D-873-49 D381-49 Fuel Mixture Gum Potential Existent (mg/100 Gum Gum ml.) (mg/100 (mg./100

ml.) ml.)

Hi-Test Gas line (Blank) 9.0 9.0 3.0 Hi-Test Gasoline 0.01% LFI 16.0 12.0 6. 0

in which each R represents an alkyl group having from 8 to 18 carbon atoms.

2. The composition defined in claim 1, in which the mixture is dissolved in alight solvent of petroleum origin as fluidizing agent.

3. The composition defined in claim 1, in which the mixture contains percent by weight of said dimethyl dialkyl ammonium chloride and 90 percent by weight of said polymerized linoleic acid.

4. A solution consisting essentially of about 40% by weight of the composition defined in claim 1 in about 60% by weight of Stoddard Solvent.

5. An inhibited light petroleum fuel of the group consisting of JP4 jet fuels and hi-test gasoline containing a corrosion inhibitor composition consisting essentially of a mixture of from about 90 to about 70% by weight of polymerized linoleic acid and from about 10 to about by weight of an oil-soluble dimethyl dialkyl ammonium chloride of the formula wherein each R represents an alkyl group having from 8 to 18 carbon atoms, said corrosion inhibitor composition being present in said fuel in an amount upwards from 12 p. p. m. in the case of a JP4 jet fuel and in an amount upwards from 6 p. p. m. in the case of a hi-test gasoline.

References Cited in the file of this patent UNITED STATES PATENTS 2,632,695 Landis et a1. Mar. 24, 1953 2,659,693 Lytle Nov. 17, 1953 2,676,987 Lewis et al. Apr. 27, 1954 OTHER REFERENCES Baker et al.: Ind. and Eng. Chem., vol. 41, No. 1, January 1949, pp. 137-144. 

1. A CORROSION INHIBITOR COMPOSITION FOR USE IN JP4 JET FUELS AND HI-TEST GASOLINE, SAID COMPOSITION CONSISTING ESSENTIALLY OF A MIXTURE OF FROM ABOUT 90 TO 70% BY WEIGHT OF POLYMERIZED LINOLEIC ACID AND FROM ABOUT 10 TO ABOUT 30% BY WEIGHT OF AN OIL-SOLUBLE DIMETHYL DIALKYL AMMONIUM CHLORIDE OF THE FORMULA 